采用恒流充放电方法测量了温度升高导致ＬｉＭｎ２Ｏ４正极容量衰减的情况．发现当环境温度上升到５０℃时，ＬｉＭｎ２Ｏ４电极出现严重的容量损失和性能衰退，充电态的电极受影响的程度最为严重．对电解液的原子发射和红外光谱分析，电极晶相结构Ｘ＿射线衍射及循环伏安实验研究表明：随着温度升高，ＬｉＭｎ２Ｏ４中阳离子混乱度增大形成无序尖晶石结构，锰离子的溶解度迅速增加，电解液出现催化氧化是导致容量不可逆衰减的原因．采用富锂尖晶石材料是抑制ＬｉＭｎ２Ｏ４高温性能下降的一种有效方法
The capacity loss of spinel LiMn2O4 cathode at elevated temperatures was evaluated by constant current charge_discharge methods and it was found that serious capacity loss and cycleability decrease occured at above 50 , especially for the charged cells. The mechanisms for this phenomena were examined by atomic emission and infrared spectrometry of the electrolyte, XRD measurment of the cycled elecrode and microelectrode voltammetry of LiMn2O4 at room and elevated temperatures. The results showed that with increasing temperature, Mn and Li ions tended to redistribute partly in the spinel framework due to the disproportion of Mn3+ ions and this results in a rapid increase in Mn dissolution and a catalytic decomposition of the electrolyte. All these factors combiningly play a dominated action for the observed capacity fading of LiMn2O4 electrode.
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